Risk Adjustment Instruments in Administrative Data Studies: A Primer for Neurosurgeons

Barriers and facilitators for using administrative data for surveillance purpose: a narrative overview

Although administrative data are not originally intended for surveillance purposes, they are frequently used for monitoring public health and patient safety. This article provides a narrative overview of the barriers and facilitators for the use of administrative data for surveillance, with a focus on healthcare-associated infection (HAI) in Canada. In this case, only articles on administrative data in general or related to HAI were included. Validation study and meta-analyses on administrative data accuracy were excluded. Medline, Embase and Google Scholar were searched as well as references list of all included articles, for a total of 90 articles included. Our analysis identified 78 barriers at the individual, organizational and systemic levels and outlined 75 facilitators and solutions to improve administrative data utilization and quality. This narrative overview will help to understand barriers, facilitators and offer practical recommendations for optimizing the use of administrative data.

Benchmarking short-term postoperative mortality across neurosurgery units: is hospital administrative data good enough for risk-adjustment?

BACKGROUND

Surgical mortality indicators should be risk-adjusted when evaluating the performance of organisations. This study evaluated the performance of risk-adjustment models that used English hospital administrative data for 30-day mortality after neurosurgery.

METHODS

This retrospective cohort study used Hospital Episode Statistics (HES) data from 1 April 2013 to 31 March 2018. Organisational-level 30-day mortality was calculated for selected subspecialties (neuro-oncology, neurovascular and trauma neurosurgery) and the overall cohort. Risk adjustment models were developed using multivariable logistic regression and incorporated various patient variables: age, sex, admission method, social deprivation, comorbidity and frailty indices. Performance was assessed in terms of discrimination and calibration.

RESULTS

The cohort included 49,044 patients. Overall, 30-day mortality rate was 4.9%, with unadjusted organisational rates ranging from 3.2 to 9.3%. The variables in the best performing models varied for the subspecialties; for trauma neurosurgery, a model that included deprivation and frailty had the best calibration, while for neuro-oncology a model with these variables plus comorbidity performed best. For neurovascular surgery, a simple model of age, sex and admission method performed best. Levels of discrimination varied for the subspecialties (range: 0.583 for trauma and 0.740 for neurovascular). The models were generally well calibrated. Application of the models to the organisation figures produced an average (median) absolute change in mortality of 0.33% (interquartile range (IQR) 0.15-0.72) for the overall cohort model. Median changes for the subspecialty models were 0.29% (neuro-oncology, IQR 0.15-0.42), 0.40% (neurovascular, IQR 0.24-0.78) and 0.49% (trauma neurosurgery, IQR 0.23-1.68).

CONCLUSIONS

Reasonable risk-adjustment models for 30-day mortality after neurosurgery procedures were possible using variables from HES, although the models for trauma neurosurgery performed less well. Including a measure of frailty often improved model performance.

Predicting in-hospital mortality for MIMIC-III patients: A nomogram combined with SOFA score

Predicting the mortality of patients provides a reference for doctors to judge their physical condition. This study aimed to construct a nomogram to improve the prediction accuracy of patients' mortality. Patients with severe diseases were screened from the Medical Information Mart for Intensive Care (MIMIC) III database; 70% of patients were randomly selected as the training set for the model establishment, while 30% were used as the test set. The least absolute shrinkage and selection operator (LASSO) regression method was used to filter variables and select predictors. A multivariable logistic regression fit was used to determine the association between in-hospital mortality and risk factors and to construct a nomogram. A total of 9276 patients were included. The area under the curve (AUC) for the clinical nomogram based on risk factors selected by LASSO and multivariable logistic regressions were 0.849 (95% confidence interval [CI]: 0.835-0.863) and 0.821 (95% CI: 0.795-0.846) in the training and test sets, respectively. Therefore, this nomogram might help predict the in-hospital mortality of patients admitted to the intensive care unit (ICU).

Outcomes of Endovascular Aneurysm Repair with Adjunctive Stenting

OBJECTIVE

Endovascular aneurysm repair is the standard of care for abdominal aortic aneurysm repair, however data regarding adjunctive stenting at the time of endovascular aneurysm repair (EVAR) are limited. The study aims to evaluate outcomes of patients undergoing EVAR with and without adjunctive stenting.

METHODS

Patients undergoing EVAR with stenting (EVAR-S) and without stenting (EVAR) (2008 to 2017) were selected from Cerner HealthFacts® database using ICD-9 diagnosis and procedure codes. Chi-square analysis and multivariable logistic regression were used to evaluate the association of patient characteristics with medical and vascular outcomes.

RESULTS

4,957 patients undergoing EVAR procedures were identified (3,816 EVAR and 1,141 EVAR-S). Demographic analysis revealed that patients who underwent EVAR-S had higher Charlson comorbidity scores (2.35 vs. 2.13, p = .0001). EVAR-S was associated with a greater frequency of vascular complications such as thrombolysis/percutaneous thrombectomy (0.9% vs. 0.2%; p < .0004). There were no differences seen in access complications between EVAR and EVAR-S. Multivariable analysis revealed that EVAR-S was associated with prolonged length of stay (OR 1.37, 95% CI 1.03-1.82), readmission < 30 days (OR 1.36, 95% CI 1.11-1.68), major adverse cardiac events (OR 1.59, 95% CI 1.09-2.32), respiratory complications (OR 1.47, 95% CI 1.16-1.88) and renal failure (OR 1.57, 95% CI 1.16-2.11).

CONCLUSIONS

Endovascular aneurysm repair with adjunctive stenting (EVAR-S) was associated with vascular complications requiring reintervention, although the overall rate was very low. As well, readmission within 30 days, cardiac complications, respiratory problems and renal failure were more likely when compared to standard EVAR. The need for adjunctive stenting acts as a marker for an overall sicker and more complex population, not just in terms of vascular complications but across all medical complications as well. Staging the procedure may be helpful in terms of spreading out the operative risk into smaller portions. Furthermore, consideration of a non-operative strategy should be discussed with the patient if the risk of the procedure outweighs the risk of aneurysm rupture in high-risk groups.

Length of stay, readmission, and mortality after primary surgery for pediatric spinal deformities: a 10-year nationwide cohort study

BACKGROUND CONTEXT

Extended length of stay (extLOS) and unplanned readmissions after first time pediatric spinal deformity surgery are a considerable challenge to both the patient and the health-care system. To our knowledge, only a limited number of nationwide studies reporting short-term comorbidity with complete follow-up exist.

PURPOSE

The purpose of this study was to identify the postoperative complications leading to extLOS, readmissions, and mortality within 90 days after surgery. Furthermore, to identify risk factors for readmission.

DESIGN

Retrospective national cohort study.

PATIENT SAMPLE

A nationwide registry study including all pediatric spinal deformity patients (≤21 years of age) undergoing primary surgery during 2006-2015 (n=1,310).

OUTCOME MEASURES

Reasons for extLOS and 90-day readmissions as well as mortality risk.

METHODS

Patients were identified by procedure and diagnosis codes in the Danish National Patient Registry (DNPR). Data on length of stay (LOS), readmissions, and mortality within 90 days were retrieved from the DNPR. Patients were categorized in six groups according to etiology. Reasons for extLOS and readmission were collected from medical records and discharge summaries.

RESULTS

For the 1,310 patients, the median LOS was 8 days (interquartile range 7-9). Etiologies were idiopathic deformity (53%), neuromuscular deformity (23%), congenital/structural deformity (9%), spondylolisthesis (7%), Scheuermann kyphosis (5%), and syndromic deformity (3%). A total of 274 (21%) patients had extLOS and the most common reason was pain/mobilization issues but with considerable variation between etiologies; Scheuermann kyphosis (91%), idiopathic (59%), syndromic (44%), spondylolisthesis (38%), and congenital (30%). Pulmonary complications were the primary reason for extLOS in the neuromuscular group (22%). The 90-day readmission rate was 6%; 67% of readmissions were medical, mainly infections unrelated to the surgical site (23%); 33% of readmissions were surgical and 14% of patients required revision surgery. Neuromuscular deformity, spondylolisthesis, Scheuermann kyphosis, and LOS >9 days were independent risk factors for readmission; odds ratio (OR) 4.4 (95% confidence interval: 2.2-9.1, p<.01), OR 3.0 (1.1-8.0, p=.03), OR 4.9 (1.7-13.6, p<.01), and OR 1.8 (1.0-3.1, p=.04), respectively. The 90-day mortality risk was 0.4%.

CONCLUSIONS

In this nationwide cohort, pain/mobilization issues are the most common reason for extLOS. The most common reason for readmission is infection unrelated to the surgical site. Readmission after pediatric spinal surgery is related to the etiology and increased focus on patients operated for neuromuscular deformity, spondylolisthesis and Scheuermann kyphosis is warranted.

Effects of Medical Comorbidities on the Surgical Outcomes of Deep Brain Stimulation for Parkinson Disease: A Retrospective, Single-Institution Study

OBJECTIVE

Advancing age and greater number of medical comorbidities are well-known risk factors for higher rates of surgical complications and undesirable outcomes. We sought to determine the risk of increasing medical comorbidities on surgical outcomes for patients with Parkinson disease undergoing deep brain stimulation (DBS) surgery.

METHODS

We retrospectively reviewed 107 consecutive patients who underwent DBS for Parkinson disease at Ochsner Medical Center in 2008-2018. Patients were stratified into 3 groups based on Elixhauser comorbidity index (ECI) at the time of surgery: 0, 1, or ≥2. Outcome measures were changes in Unified Parkinson's Disease Rating Scale III scores, changes in medications, and surgical complications. Analysis of variance, paired t test, and nonparametric equivalents were used for statistical analysis.

RESULTS

Of patients, 31 (29.0%) had ECI score 0, 44 (41.1%) had ECI score 1, and 32 (29.9%) had ECI score ≥2. For all groups, Unified Parkinson's Disease Rating Scale III scores decreased significantly postoperatively (P = 0.0014, P < 0.0001, P < 0.0001). All groups had a reduction in mean levodopa equivalent daily dose after surgery; however, only the group with ≥2 comorbidities achieved statistical significance (P = 0.0026). The rate of postoperative complications was significantly correlated with comorbidity score on univariate logistic regression analysis (P = 0.0425).

CONCLUSIONS

Our findings indicate that DBS is efficacious in patients with multiple medical comorbidities. However, patients with ≥1 medical comorbidities may be more likely to have complications. The most common observed complication was wound infection. Patients with medical comorbidities may still benefit significantly from DBS when performed at experienced centers.